Product Description:

The X20BB22 is a backplane bus module produced by B&R Automation for the X20 Fieldbus Input Output Modules series. Installed on an X20 rack, the unit forms a communication segment and supplies distribution power to attached I/O slices. In an automation cell, it acts as the mechanical and electrical base that ties discrete and analog channels to higher-level controllers through the system bus. This arrangement lets adjacent modules exchange power and data through the rack structure instead of requiring separate interconnect wiring between each slice.

It draws only 0.32 W from the backplane, so its thermal contribution inside a panel remains low even in densely packed racks. The module accepts a system supply of 24 VDC, matching the standard control voltage used in many machine cabinets. For device communication, a front-mounted 1x RS232 connection provides a point-to-point serial link for compatible external devices. The housing has an IP20 rating, so it is intended for protected enclosure installation rather than direct exposure on the machine. Installation flexibility is improved because the module supports horizontal or vertical orientations without changing its intended function on the rack.

A contact path inside the bus permits up to 10 A of load current to pass through the terminal chain, allowing several powered slices to share the same supply feed. Mechanical spacing is fixed by a module pitch of 37.5 +0.2 mm, which helps keep rack layouts consistent when multiple stations are planned side by side. Operation remains rated at altitudes up to 2000 m. Above that height, the allowable ambient temperature is reduced by 0.5 °C/100 m. These operating limits help determine where the module can be installed in distributed control systems that use elevated cabinets or plant mezzanines.